Guide apparatus of steam turbines



Aug. 11, 1 925. 1,549,209

F. NoBs GUIDE. APPARATUS 0F STEAM TURBINES Filed Sept. 18, 1924 15y c k r Figfia h, Fig.3; a z [34 k e F fic b Y Fig lfi Patented Aug. 11, 1925.

PATEN FFHCE.

FB'ITZ NOBS, OF ENNETBADEN, SWITZERLAND, ASSIGNOR vTO AKTIENGESELLSCHAFT BROWN, BOVERI AND 01111,

035 BADEN, SWITZERLAND.

GUIDE APPARATUS O'F STEAM TURBINES,

Application filed September 18, 1924. Serial No. 738,486.

To all whom it may concern:

Be it known that I, Fnrrz NoBs, a Swiss citizen, residing at Ennetbaden, Switzerland, have invented certain new and useful Improvements in the Guide Apparatus of Steam Turbines, of which the following is a specification.

It has already been proposed to construct the guide apparatus of the diaphragms in steam turbines by casting guide plates in these diaphragms or by bolting complete sections of guide blades upon the said diaphragms. It has already been proposed to construct the blading of the diaphragms 1n the same way as is done in the case of the rotors. It has been furthermore proposed to constitute one boundary wall of the guide passages by the actual diaphragm, and to constitute the other boundary wall by means of a separate guide ring portion. In such a construction the guide blades are carried either by the diaphragm or by the said guide ring portion.

The present invention has for its object to provide improvements in the last mentioned system of construction and fastening of the guide apparatus of the diaphragms, which shall allow of an accurate and cheap manufacture, and is designed chiefly for use in turbines of small rotor diameters or of high pressure-stages, where small lengths of the blades are predominant.

The present invention consists broadly in the insertion of a guide ring portion as aforesaid into a corresponding annular groove in the diaphragm, said guide ring portion being formed with a conical bearing surface on the side next the casing, so that, in addition to its attachment by means of the special fastening bolts, the said guide ring portion is also pressed steam-tight by the steam pressure acting upon the diaphragm, in the same manner as is already known in the case of covering rings mounted on the outer periphery of diaphragms having guide passages opening outwards.

In the accompanying drawings Figs. 1 and 2 illustrate a constructional example of an improved guide apparatus of this invention, in two sections taken at right angles to each other through the respective.

part of the turbine.

Figure 3. is a section of the diaphragm alone.

Figures 8 3 and 3 show the ring portion with integral blades milled therefrom with blades cast therein and with blades inset therein respectively.

Figure 4 and 5 are sections of the diaphragms with blades milled therefrom and with blades cast therein respectively and Figures 4 and 5 represent the ring portion in section for Figures f and 5 respectively.

In these figures: a is a diaphragm; b is a guide ring portion bearing with a conical surface 0 upon the casing cl; and e is a rotor. The steam pressure upon the diaphragm is taken by strong ribs 7. The conical shape of the bearing surface 0 not only effects an axial jointing of the surface g, but also acts to press the ends of the blades radially against the inner boundary surface it.

The blades 70 of the guide apparatus may be formed by milling out of the solid ring portion or by any other suitable known means. As the passages are open inwards, it is possible to achieve accuracy of manufacture, a good design of the proportions of the cross sections and the angles, and to obtain smooth surfaces.

This improved manner of fastening may of course, be employed for the first group of nozzles of a turbine.

Instead of mounting the guide blades 70 on the ring portions 6, they may be fastened directly to the diaphragm a. In such a case the blade-less ring portion 6 would serve as a covering ring for the blade passages, and, as before, act to the joint the jointing surface g as well as the outer boundary surface Z of the guide apparatus.

What I claim is 1. A. guide apparatus for the diaphragms of steam turbines having ring portions which are made separate from the diaphragms and which constitute one boundary wall of the guide passages, the other boundary wall being constituted by the respective diaphragm, characterized by the feature that the ring portion is provided with a conical surface bearing upon a corresponding conical surface on the turbine casing, a cylindrical surface bearing upon a corresponding surface on the diaphragm and an annular surface, substantially at right angles to the aXis'of the turbine, bearing upon a corresponding complete annular surface on the diaphragm, the diaphragm, ring 2. A guide apparatus as claimed in claim portion and the casing being so arranged 1, characterized by the feature that the that steam pressure on the diaphragm causes blades are milled out of the ring portion. 10 the ring portion to be pressed against the 111 mo y Wh r ffi I have Signed my 5 conical surface of the. casing and thus also name to this peclfic t onagainst the cylindrical surfaceon the diaphragm. p FRITZ NOBS, 

